Answer:

Step-by-step explanation:
Answer:
The first step is to replace the y in y-x=15 with 7x (we can do this because the first equation tells us that they're equal)
solve and get
(2.5,17.5)
or x= 2.5 y=17.5
Step-by-step explanation:
The first step is to recognize that y=7x which means that we can just replace the y in the second equation with 7x
7x-x=15
6x=15
x=2.5
Then we can solve for y
y=7(2.5)
y=17.5
Answer:
I believe it should be b and d
Step-by-step explanation:
hoped it helped :)
Answer:
21
Step-by-step explanation:
There are 9,000 markers in total
750 x 12 = 9,000